1. Field of the Invention
The present invention relates to a device constituting a wall, partition, or curtain for damping water movement(s) and intended more particularly for damping the slipstreams induced by the propellers of ships, and also chop and swell of small amplitude. It is intended more particularly to be installed vertically within pontoons on piles, more precisely under said pontoons and between the supporting piles in port installations.
2. Discussion of Related Art
A port is a space in which ships maneuver, with the help of their thrusters (propellers and/or bow thrusters in particular), in particular for docking or for leaving the quayside where they were moored. Such thrusters deliver slipstreams that can propagate over long distances and that can give rise to scouring that is limited or eliminated by anti-scouring devices that are generally placed at the bottoms of structures or in sensitive zones. Such thruster slipstreams can also lead to discomfort or difficulties in docking for certain boats situated nearby.
The movement of ships also gives rise to waves of short period, thus also interfering with boats, in particular yachting or fishing boats, in the same manner as chop generated by local winds.
In port environments, it is generally desirable to create protected zones in which the surface of the water remains calm, and numerous techniques have already been developed for creating such sheltered zones, and mention can be made of uninterrupted breakwaters, interrupted breakwaters, Jarlan type rigid perforated walls, and caisson walls. With all those techniques, the idea is either to reflect a wave, causing it merely to head back out to sea, or else to dissipate the intrinsic energy in the mass of moving water, either by transforming it directly into heat within the mass of water (uninterrupted or partial breakwaters), or by recovering the energy so as to transform it into electricity (tidal amplitude chambers), or indeed by creating phase shifts within the waves as occurs with caisson walls.
All of those systems present great effectiveness in absorbing strong swell and more particularly short swell. However, they are in general works of considerable mass since they need to withstand very large forces and to do so over durations exceeding 30 years to 50 years or even more.
The solution that consists in “waterproofing” quays of the type that are built on piles is not always desirable (even ignoring the extra cost), since that leads to unwanted reflections having the effect of increasing roughness, in particular at the end of a dock or along a straight quay, thereby reducing the comfort and the workability of berths along the quay.
With the exception of uninterrupted breakwaters that create a total screen, interrupted breakwaters, and caisson walls are not very effective in damping waves of long wavelength and chop generated by turbulent currents around the piles or created by ships' propellers while the ships are approaching their mooring points on a pontoon.
Patent WO 02/26019 describes a device that seeks to dissipate wave energy, the device comprising an array of floating modules of plastics material assembled together by a system of flexible rubber hinges, both in the vertical direction and in the horizontal direction, forming a system that is relatively complex and expensive to make, and also relatively fragile.
The complexity of the device described in WO 02/26019 comes from the particular shape of the modules defining particular openings, and from the shape of the assembly elements outside said modules.
In addition, the flexibility of the hinge system of WO 02/26019 constituted by resilient rubber assembly elements external to the various floating modules gives that device as a whole excessive mobility, leading to phenomena of wear and limited lifetime.